i965: Set up swizzling of shadow compare results for GL_DEPTH_TEXTURE_MODE.

The brw_wm_surface_state.c handling of GL_DEPTH_TEXTURE_MODE doesn't
apply to shadow compares, which always return an intensity value.  The
texture swizzles can do the job for us.

Fixes:
glsl1-shadow2D(): 1
glsl1-shadow2D(): 3

diff --git a/src/mesa/drivers/dri/i965/brw_wm.c b/src/mesa/drivers/dri/i965/brw_wm.c
index 9ca8e70..6610640 100644 (file)
--- a/src/mesa/drivers/dri/i965/brw_wm.c
+++ b/src/mesa/drivers/dri/i965/brw_wm.c
@@ -342,13 +342,44 @@ static void brw_wm_populate_key( struct brw_context *brw,
       if (unit->_ReallyEnabled) {
          const struct gl_texture_object *t = unit->_Current;
          const struct gl_texture_image *img = t->Image[0][t->BaseLevel];
+
+        key->tex_swizzles[i] = SWIZZLE_NOOP;
+
+        /* GL_DEPTH_TEXTURE_MODE is normally handled through
+         * brw_wm_surface_state, but it applies to shadow compares as
+         * well and our shadow compares always return the result in
+         * all 4 channels.
+         */
+        if (t->CompareMode == GL_COMPARE_R_TO_TEXTURE_ARB) {
+           if (t->DepthMode == GL_ALPHA) {
+              key->tex_swizzles[i] =
+                 MAKE_SWIZZLE4(SWIZZLE_ZERO,
+                               SWIZZLE_ZERO,
+                               SWIZZLE_ZERO,
+                               SWIZZLE_X);
+           } else if (t->DepthMode == GL_LUMINANCE) {
+              key->tex_swizzles[i] =
+                 MAKE_SWIZZLE4(SWIZZLE_X,
+                               SWIZZLE_X,
+                               SWIZZLE_X,
+                               SWIZZLE_ONE);
+           }
+        }
+
         if (img->InternalFormat == GL_YCBCR_MESA) {
            key->yuvtex_mask |= 1 << i;
            if (img->TexFormat == MESA_FORMAT_YCBCR)
                key->yuvtex_swap_mask |= 1 << i;
         }
 
-         key->tex_swizzles[i] = t->_Swizzle;
+        key->tex_swizzles[i] = MAKE_SWIZZLE4(GET_SWZ(key->tex_swizzles[i],
+                                                     GET_SWZ(t->_Swizzle, 0)),
+                                             GET_SWZ(key->tex_swizzles[i],
+                                                     GET_SWZ(t->_Swizzle, 1)),
+                                             GET_SWZ(key->tex_swizzles[i],
+                                                     GET_SWZ(t->_Swizzle, 2)),
+                                             GET_SWZ(key->tex_swizzles[i],
+                                                     GET_SWZ(t->_Swizzle, 3)));
       }
       else {
          key->tex_swizzles[i] = SWIZZLE_NOOP;